During the energy crisis of the 1970's, the Biodigester was presented as an alternative for the generation of thermal energy, as it produces Biogas.

In reality however, a biodigester produces gas is in very small quantities, and is not feasible to justify the construction of a biodigester for the sole purpose of it's production and use for thermal energy, and much less for the obtainment of carbon dioxide of even sulfide acid.

The real value of a biodigester, is in the fertilizer it produces, known as Biofertilizer, and in the hygienic alternative it provides to us to conventional organic fertilizers.

The end product of the various phases of Biodigestion, is a liquid which is dark in colour due to the presence of Humus in it.

We call this Pure Biofertilizer, and it can be used on soil as a high quality organic fertilizer, or even as a corrector of pH, bacterial life and texture.

The Biofertilizer has a relative high nutrient concentration, and even so, it can be used directly over soil before planting.

It is very valuable when it is used as an additive in the preparation of Nutrient Solutions for Organo-Inorganic Hydroponics, and here, it promotes extremely high crop levels.

Once diluted, it constitutes a high quality foliar fertilizer, and in this form, it is known as Diluted Biofertilizer.

Diluted Biofertilizer also has all the needed conditions to be used as a complete Nutrient Solution in Organic Hydroponics.

The advantages of using the biofertilizer are enormous, not only it is very economical, but also for the high agricultural yelds which it produces.

It is possible however, that the biofertilizer may not be the most adequated fertilizer for all kinds of plants.

It's composition can present many variations, depending the types or organic matter used to feed the Biodigester that produces it.

So, to get a consistent composition of the biofertilizer, we must mantain consistence in the kind, quality and composition of the Organic Matter used in its production.

The correct use of a biofertilizer, is the principal key for us to get the highest rates of agricultural productivity, and for that, some rules should be observed, as follows:

1 - To carry periodically Chemical and Physical analysis of the biofertilizer, to determine it's chemical composition ans it's water solubility.

If we have not too many variations in the composition of the organic matter we feed the biodigester, a monthly analysis is sufficient.

2 - To conduct a Chemical and Physical analysis of the soil which we plan to cultivate, to determine the components of that soil, and their solubility degree.

3 - To identify in speciallized literature or by means of chemical analysis, the characteristics of the plants we plan to cultivate.

With this information, we can correct the chemical composition of the biofertilizer, adding to it the various soluble nutrients required.   We call this operation the Mineralization of the Biofertilizer.

It is likely that the process of mineralization is not an easy operation for many farmers, and for those, it is advisable to obtain the assistance of an agronomist.

These procedures should be observed when we use the biofertilizer to prepare Nutrient Solutions for hydroponics.